Columbia University's Health Science Division(CUHSD) receives approximately 39 million dollars annually in direct costs for sponsored projects that use animals. Since 1986, the CUHSD has been engaged in a Master Plan to revitalize its program in laboratory animal care and use, and to renovate its laboratory animal facilities. Approximately 15 million dollars have been committed to this Master Plan which will be completed in 1992. Over the past 3 years, the use of transgenic mice by faculty within the Hammer Health Sciences Building has sharply risen. It is anticipated that this use will continue to increase with the addition of new faculty now being recruited. The Institute of Comparative Medicine became solely responsible for the animal care program at the Hammer Building's laboratory animal facility late in 1988. A significant problem within the facility is that mouse hepatitis virus (MHV) and Sendai virus are endemic. These infections are particularly troublesome to research in molecular genetics because of the nature of transgenic mouse use. This grant proposal requests assistance in addressing needs for pathogen-free transgenic mice and for increasing the amount of space available for housing transgenic mice. The objectives of the project are (1) To create a barrier facility within the Hammer Building that will enable investigators to maintain pathogen-free mice. This will be achieved through modification of space, use of micro-isolators and operational procedures, and (2) To increase the available amount of animal housing space by approximately 40%. This will be accomplished by reducing the high ratio of corridor-space to gross-space within the facility.